Connectivity Software User's Guide and Reference
Examples - Server OPC UA - Provide data variable status code in read function

.NET

// This example shows how to create a data variable and implement reading its attribute data using a function, providing
// "Good" or "Bad" status code as needed.
// You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server. 
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Generic;
using OpcLabs.EasyOpc.UA.NodeSpace;

namespace UAServerDocExamples._UADataVariable
{
    partial class ReadFunction
    {
        public static void Unreliable()
        {
            // Instantiate the server object.
            // By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
            var server = new EasyUAServer();

            // Create a data variable, defining its read attribute data (including status code and source timestamp) by a
            // function. Alternate "Good" and "Bad" status codes randomly.
            // The type of the data variable (Int32, in this case) is inferred from the type returned by the function.
            var random = new Random();
            server.Add(new UADataVariable("ReadThisVariable").ReadFunction(() => new UAAttributeData<int>(
                value: 42,
                (random.Next(2) != 0) ? UACodeBits.Good : UACodeBits.BadNoCommunication,
                DateTime.UtcNow)));

            // Start the server.
            Console.WriteLine("The server is starting...");
            server.Start();

            Console.WriteLine("The server is started.");
            Console.WriteLine();

            // Let the user decide when to stop.
            Console.WriteLine("Press Enter to stop the server...");
            Console.ReadLine();

            // Stop the server.
            Console.WriteLine("The server is stopping...");
            server.Stop();

            Console.WriteLine("The server is stopped.");
        }
    }
}
# This example shows how to create a data variable and implement reading its attribute data using a function, providing
# "Good" or "Bad" status code as needed.
# You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server. 
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.Generic
using namespace OpcLabs.EasyOpc.UA.NodeSpace
using namespace OpcLabs.PowerShellManagement

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.ServerOpcUAComponents.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.PowerShellManagement.dll"

# Instantiate the server object.
# By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
$server = New-Object EasyUAServer

# Create a data variable, defining its read attribute data (including status code and source timestamp) by a
# function. Alternate "Good" and "Bad" status codes randomly.
# The type of the data variable (Int32, in this case) is inferred from the type returned by the function.
$random = New-Object System.Random
$server.Add([UADataVariableExtension]::ReadFunction((New-Object UADataVariable("ReadThisVariable")), [RunspacedDelegateFactory]::NewRunspacedDelegate([System.Func[UAAttributeData[int]]] { New-Object UAAttributeData(42, $(if ($random.Next(2) -ne 0) {[UACodeBits]::Good} else {[UACodeBits]::BadNoCommunication}), [DateTime]::UtcNow) }) ))

# Start the server.
Write-Host "The server is starting..."
$server.Start()

Write-Host "The server is started."
Write-Host

# Let the user decide when to stop.
Write-Host "Press Enter to stop the server..."
Read-Host

# Stop the server.
Write-Host "The server is stopping..."
$server.Stop()

Write-Host "The server is stopped."
' This example shows how to create a data variable and implement reading its attribute data using a function, providing
' "Good" or "Bad" status code as needed.
' You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server. 
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports System
Imports Newtonsoft.Json.Linq
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.Generic
Imports OpcLabs.EasyOpc.UA.NodeSpace

Namespace Global.UAServerDocExamples._UADataVariable
    Partial Friend Class ReadFunction
        Shared Sub Unreliable()
            ' Instantiate the server object.
            ' By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
            Dim server = New EasyUAServer()

            ' Create a data variable, defining its read attribute data (including status code and source timestamp) by a
            ' function. Alternate "Good" and "Bad" status codes randomly.
            ' The type of the data variable (Int32, in this case) is inferred from the type returned by the function.
            Dim random = New Random()
            server.Add(New UADataVariable("ReadThisVariable").ReadFunction(Function() New UAAttributeData(Of Integer)(
                42,
                If(random.Next(2) <> 0, UACodeBits.Good, UACodeBits.BadNoCommunication),
                DateTime.UtcNow)))

            ' Start the server.
            Console.WriteLine("The server is starting...")
            server.Start()

            Console.WriteLine("The server is started.")
            Console.WriteLine()

            ' Let the user decide when to stop.
            Console.WriteLine("Press Enter to stop the server...")
            Console.ReadLine()

            ' Stop the server.
            Console.WriteLine("The server is stopping...")
            server.Stop()

            Console.WriteLine("The server is stopped.")
        End Sub
    End Class
End Namespace
See Also

OPC Wizard